Left: H₂CO rotational temperature map of the IRS7 region from SMA/APEX data. Temperatures are in K. Right: p-H₂CO LTE column density map of the IRS7 region. The colour scale bar shows values in log ₁₀N, where N is given in cm^-2. Both maps use the integrated intensities of three para-H₂CO lines around 218 GHz, and only data points that are inside the SMA primary beams and where all three lines have 5σ detections or stronger are considered. All other points are represented by white pixels. The temperatures and column densities are calculated with rotational diagrams for line intensities integrated between 0 and 9 km s^-1. The contours show the integrated intensity of the H₂CO 3₀₃–2₀₂ line in the same velocity interval, with contours every 2 K km s^-1 (~3σ at the edge of the primary beam). Refer to Fig. 1 for a guide to the symbols used for the compact objects.